Turn on the broiler, glow plug glows and about 30 seconds later the gas comes on. Do the same thing with the "bake" burner, the glow plug glows and glows and glows and.... gas never comes on. Any ideas how to troubleshoot this? Also it's built in, I can imagine this might be a PITA to work on.

Most common is oven glowcoil. Amp probe is the best way to check,draws 3.2-3.6 amps to open oven safety.Loop amp probe over 1 wire on the glowcoil and get readings. Before complete failure did it take a long time to come on? Gas build up? Glowcoils last on average 4-6 years depending on oven use.

The glow plug for the bake burner appears to start glowing at about the same time the broiler glow plug started to glow(not at the same time though, I used the timing for the broiler to check the timing on the bake burner). Instead of the gas coming out after about 30 seconds like the broiler burner, it just continues to glow for 4 or 5 minutes and no gas smell....The burner never comes on.

I will check the amp draw on the glow plug for the burner. I'm guessing from your post the amp draw determines whether it's safe to turn the gas on, so something must be monitoring the amps. If it's out of the range your post has, should I figure on replacing the glow plug, even though it glows?

What happens is the glow coil receives 110 volts from the control, once it gets hot enough it allows about 3-4 volts to the valve and lets it open. As the coil gets older it wears out only allowing as an example 2 volts to the valve. 90% of gas oven no light failure is the gas coil, I rarely change a valve.

Just had this same scenario the other day. Bake ignitor/glowbar only pulling 2.6 amps and would take 5-10 minutes to ignite, and could barely hold that gas coil open. It actually closed a few times. Broil ignitor/glowbar pulled 3.4 amps immediately and has ignition shortly after. Bake ignitor gets used much more often. If you want, the upper and lower glowbars should be interchangeable. You can swap them both out and can be done through the front.